1. Field of the Invention
The present invention relates to a receiver for digital radio communications, and more particularly to a receiver for digital mobile radio communication.
2. Description of the Related Art
Digital mobile radio communication demand elimination of multipath fading that occurs due to the reception of radio waves reflected by different objects including surrounding topographic features, buildings, structures, etc. Actually, the reflected radio waves received by a receiver rarely suffer large differences in arrival time. If, however, reflected radio waves arrive at a receiver with substantially different time delays, then they are subject to waveform distortion. Adaptive equalization has been proposed to compensate for such waveform distortion.
There has been a demand for the addition of an adaptive equalizer to an ordinary demodulator in a receiver for digital mobile radio communication. The adaptive equalizer comprises a digital signal processor because it requires highly complex signal processing for adaptive equalization. One example of such an adaptive equalizer is described in detail in the article "Designing of Adaptive Maximum Likelihood Series Estimator And Its Characteristics Under Selective Fading", by Kubo, Murakami and Fujino, page 391, Collected Lecture Papers No. 2, National Spring Conference of Electronic Communications Society, published in 1991. However, that adaptive equalizer employing a digital signal processor requires a large amount of power consumption and hence does not lend itself to being incorporated in a portable receiver.